High Voltage Hacks: Transmute the elements in your garage

The magnum opus of alchemy was the Philosopher’s stone, a substance that was able to turn common metals into gold. Unlike alchemists, [Carl Willis] might not be poisoning himself in a multitude of ways, but he did build a Farnsworth fusor that’s capable of turning Hydrogen into Helium.

To fuse Hydrogen in his device, [Carl] first evacuates a vacuum chamber. Deuterium (Hydrogen with an added neutron) is injected into the chamber, and a spherical cathode made of Tungsten is charged to 75 kV. The deuterium gas is heated and confined by the cathode and fuses into Helum. The electrostatic confinement of the plasma isn’t very much different from some old CRT tubes. This isn’t a coincidence – both the fusor and CRTs were invented by the same man.

While no fusion experiments – including some billion dollar experiments – have ever produced a net energy gain, this doesn’t mean it’s not an impressive engineering feat. If you’d like to try your hand at building your own fusor, drop by the surprisingly active research forum. There’s a lot of really good projects to look through over there.

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Nice, well documented.
Any chance someone can try my idea of using a PCB with fine tracks etched on it and covered with an insulating polymer with glass 0.05mm away and driven with a sequential drive a la Naudin ARDA as a solid state vacuum pump?

You have to ionize the plasma and you need room for acceleration otherwise you won’t get anything. The hydrogen is accelerated though the high voltage. Massive amount of energy input, it often can warp the tungsten or other materials used for the grid.

Small, low-power fusors make almost no neutrons (they’re little most then overcomplicated neon lights, the odd pair of deuterium atoms may fuse now and again, but for the most part you’re just ionizing gas and nothing more. You do need some shielding since the ions hitting the grid makes some x-rays through bremsstrahlung, but it doesn’t take that much.)

The larger, more powerful designs that can generate a decent amount of neutrons are shielded to keep them from escaping (except when they’re are being used as a neutron source, in which case you *want* the neutrons to escape)

Agh! Every so often somebody makes one of these in their garage and either they end up in the news or their kid presents it at a science fair and ends up in the news, and people briefly misunderstand what a fusor is.

On the bright side, a few more people understand the reference in Futurama.

Fusors are really cool and the guy knows what he’s doing. While I can’t agree with the blurb that implies they’re less harmful than the alchemists’ experiments long ago (they aren’t–Fusors are great neutron sources, so if you’re ignorant and don’t take precautions and measurements, very bad things will happen), they’re hard to build and operate compared to even more dangerous endeavors featured here on HAD (i.e. anything using components from a microwave oven for pretty much anything)

The technical problem with fusion is recovering the energy efficiently.

The economic problem with alternative energy is that fossil fuels are heavily subsidized and have been for decades. Coal is often mined on public land for below free market rates. When it’s mined on private land they’re allowed a depletion credit. The cost of mining pollution cleanup is passed to the general public. Coal is then transported on rail lines built with tax subsidies to power plants built with government underwritten bonds where it’s burned for a guaranteed profit in local monopolies. The toxic ash is then interned at taxpayer expense. If the internment fails, the cleanup is again at taxpayer expense. When you use electrical power from coal for a business, the expense is 100% deductible. Almost nowhere are private consumers charged full sales tax on power from coal.

By contrast, a company making solar cells must pay property tax, income tax, compete in an open market to a consumer that must pay sales tax on the panel and then their property tax goes up. When a business buys them the expense can only be capitalized instead of fully deducted that year.

Oil is even worse. 2/3 of the US trade deficit is the direct cost of oil imports. That’s about $40B per MONTH. When you consider that nuclear plants cost $2B and solar plants cost only $0.3B we should obviously be building solar plants all across the southwest.